In accordance with the popularization of mobile communication devices in recent years, miniaturization and weight reduction of them are desired for making them convenient for carrying or moving. Among electronic parts included in such a mobile communication device, miniaturization of semiconductor integrated circuit or the like is in rapid progress.
However, miniaturization of antenna is not being advanced, which hinders the miniaturization and weight reduction of mobile communication devices. Japanese Patent Laid-open No. 2000-196339 discloses an element formed in a spiral or a meander shape for miniaturizing an antenna. However, when an element is formed in the spiral or meander shape on a limited antenna forming face, portions of the element become adjacent to each other, which can cause mutual interference due to capacitive coupling or the like between the portions of the element. The mutual interference between the portions of the element decreases radiation efficiency of radio wave and hinders widening a band of radio wave, and thus it is preferred to be avoided as much as possible. The present invention is to solve the above-mentioned problems, and an object thereof is to provide a dielectric antenna which is, although being made in a small size, capable of eliminating the decrease of radiation efficiency of radio wave and the hindrance to widening the band of radio wave as much as possible by restraining the mutual interference between elements, an antenna mounting substrate and a mobile communication device including them.